Stepped headers merge into a 3-1/2'' short straight muffler body with Hot Rod turnout end cap1-3/4'' headpipe steps up to 1-7/8'' into the collector to increase flow and improve performanceRemovable spiral-core louvered baffle included Hand MIG welding18 mm and 12 mm O2 ports with adapters and plugsIncludes mounting hardwareFull heat shields includedMade in the U.S.A.